Chamberlain · Garage Door Opener Serious

1-4 — Safety sensors misaligned or obstructed

The photoelectric safety sensors are not seeing each other. The door will close only when the wall button is held down and will reverse during closing.

Keep using it?
Limited use only
DIY difficulty
Easy
Typical cost
$25-40
Verified against
chamberlain.com ↗

The fix

Chamberlain/LiftMaster Safety Sensor Kit (041-0136, replaces 41A5034)

Photoelectric safety sensors not seeing each other

$25-40 easy difficulty 30 min Tools: screwdriver

Diagnose first: Re-align both eyes so the receiver LED goes solid before replacing anything — this is free and fixes most cases.

Find this part on Amazon →

As an Amazon Associate we earn from qualifying purchases.

How to fix it

  1. Confirm both sensor LEDs: yellow on the sending side should be steady, green on the receiving side should be steady.
  2. Wipe both lenses clean with a soft cloth.
  3. Loosen the wingnut on the receiver bracket, swivel until the green LED glows steady, then tighten.
  4. Shade the receiver with cardboard temporarily — if green LED comes on, sun is the cause; install a shield or rotate the sensor.
  5. Check sensor wires at the motor head (white and white-with-black terminals). Re-strip and reconnect.
  6. If green LED never comes on, swap left/right sensors to determine which is bad and replace the pair.

Why it happens

Typical signs: 1 flash then 4 flashes on motor head · Sending sensor (yellow) LED on, receiving sensor (green) LED off or flickering · Door reverses immediately when closing · Door light flashes 10 times when remote close is pressed

  • Sensors misaligned Bracket bumped — green LED on receiver is off or dim.
  • Sun shining directly into receiver Low sun blinds the receiving (green) sensor.
  • Lens dirty or fogged Dust, spider webs, or condensation on lens.
  • Loose or broken sensor wire Wire pulled out of terminal or staple cut insulation.
  • Failed sensor Receiver no longer powers up green LED even when aligned.

More Chamberlain garage door opener codes

1-1 1-1 — Safety Sensors Obstructed/Misaligned/Disconnected 1-2 1-2 — Safety Sensor Wires Shorted or Reversed 1-3 1-3 — Door control wire issue / lock button stuck 1-5 1-5 — Motor Drive / No RPM at Start of Movement 1-6 1-6 — Unexpected RPM After Stop at Open Position 2-1 2-1 — Logic Board Component Failure

All Chamberlain codes → All garage door opener codes →

Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician. Verified against manufacturer documentation: chamberlain.com.